Serum Uric Acid as a Cardiovascular Risk Marker: Differential Effects of Ketogenic Diet and Intermittent Fasting in Postmenopausal Women

Background: Serum uric acid (UA) is increasingly recognized as a cardiovascular (CV) risk factor, with evidence suggesting that CV risk may occur at levels below conventional hyperuricemia thresholds. However, real-world comparative data on the effects of dietary interventions on UA are limited. Objective: The primary objective of this study was to compare the effects of a very low-calorie ketogenic diet (VLCKD), intermittent fasting (IF), and standard dietary advice (free diet, FD) on UA levels and UA-defined CV risk in hypertensive postmenopausal women. Methods: In this prospective, single-center, real-world clinical study, 43 women with essential hypertension and obesity underwent dietary interventions. UA levels were assessed at baseline and after 6 months. Hyperuricemia was defined using both the conventional threshold (≥6.0 mg/dL) and the CV risk-oriented Uric Acid Right for Heart Health (URRAH) cut-off (≥4.7 mg/dL). Analyses included paired tests and ANCOVA adjusted for baseline UA. Results: At baseline, over half of participants exceeded the URRAH threshold. Only VLCKD significantly reduced UA levels (-1.23 mg/dL; p < 0.001), remaining independently associated after adjustment (β = -0.95 mg/dL; p = 0.007). URRAH-defined CV risk decreased significantly only in the VLCKD group (55.6% to 22.2%), with one-third transitioning to lower risk. Conclusions: VLCKD significantly reduced UA levels and UA-defined CV risk, supporting its role as a potentially effective lifestyle intervention in this population.